We’ve all seen lots of anectodal evidence that some kinds of success, such as winning or inheriting a lot of money or becoming a celebrity, can leave you worse off, e.g. divorced, addicted to drugs, bankrupt, in jail, having wastrel children etc. On the other hand, middle class people have problems too.
My question is: Has anyone ever formally studied things to see, statistically, what the effects of success are on individuals?
First of all, winning the lottery or inheriting a fortune are not examples of success. Success is setting your own personal goals and working your ass off to achieve them. Most people who are truly successful in life are better off for it.
What you’re referring to are people who acquire unearned wealth (with the possible exception of the celebrity). What they make of their good fortune depends on their character, which has nothing to do with class.